Aims

To evaluate inducing osteoarthritis (OA) by surgical destabilization of the medial meniscus (DMM) in mice with and without a stereomicroscope.

Objectives. Platelet-rich plasma (PRP) is being used increasingly often in the clinical setting to treat tendon-related pathologies. Yet the optimal PRP preparations to promote tendon healing in different patient populations are poorly defined. Here, we sought to determine whether increasing the concentration of platelet-derived proteins within a derivative of PRP, platelet lysate (PL), enhances tenocyte proliferation and migration in vitro, and whether the mitogenic properties of PL change with donor age. Methods. Concentrated PLs from both young (< 50 years) and aged (> 50 years) donors were prepared by exposing pooled PRP to a series of freeze-thaw cycles followed by dilution in plasma, and the levels of several platelet-derived proteins were measured using multiplex immunoassay technology. Human tenocytes were cultured with PLs to simulate a clinically relevant PRP treatment range, and cell growth and migration were assessed using DNA quantitation and gap closure assays, respectively. Results. Platelet-derived protein levels increased alongside higher PL concentrations, and PLs from both age groups improved tenocyte proliferation relative to control conditions. However, PLs from aged donors yielded a dose-response relationship in tenocyte behaviour, with higher PL concentrations resulting in increased tenocyte proliferation and migration. Conversely, no significant differences in tenocyte behaviour were detected when increasing the concentration of PLs from younger donors. Conclusion. Higher PL concentrations, when prepared from the PRP of aged but not young donors, were more effective than lower PL concentrations at promoting tenocyte proliferation and migration in vitro. Cite this article: D. R. Berger, C. J. Centeno, N. J. Steinmetz. Platelet lysates from aged donors promote human tenocyte proliferation and migration in a concentration-dependent manner. Bone Joint Res 2019;8:32–40. DOI: 10.1302/2046-3758.81.BJR-2018-0164.R1

Aims. The traditional transosseus flexor hallucis longus (FHL) tendon transfer for patients with Achilles tendinopathy requires two incisions to harvest a long tendon graft. The use of a bio-tenodesis screw enables a short graft to be used and is less invasive, but lacks supporting evidence about its biomechanical behaviour. We aimed, in this study, to compare the strength of the traditional transosseus tendon-to-tendon fixation with tendon-to-bone fixation using a tenodesis screw, in cyclical loading and ultimate load testing. Materials and Methods. Tendon grafts were undertaken in 24 paired lower-leg specimens and randomly assigned in two groups using fixation with a transosseus suture (suture group) or a tenodesis screw (screw group). The biomechanical behaviour was evaluated using cyclical and ultimate loading tests. The Student’s t-test was performed to assess statistically significant differences in bone mineral density (BMD), displacement, the slope of the load-displacement curves, and load to failure. Results. The screw group showed less displacement (loosening) during cyclical loading, which was significant during 300, 500, 600, 700, 800, 900, and 1000 cycles (p < 0.05: other cycles: 0.079 < p < 0.402). Compared with the suture group, the screw group had higher mean ultimate load values (133.6 N, . sd. 73.5 vs 110.1 N,. sd. 46.2; p = 0.416). Conclusion. Fixation of the FHL tendon with a tenodesis screw enables a less invasive procedure to be undertaken and shows similar biomechanical behaviour and primary strength compared with fixation using a transosseus suture. Cite this article: Bone Joint J 2018;100-B:1175–81

While the evolution of the bony skeleton of the shoulder girdle is well described, there is little information regarding the soft tissues, in particular of the rotator cuff. We dissected the shoulders of 23 different species and compared the anatomical features of the tendons of the rotator cuff. The alignment and orientation of the collagen fibres of some of the tendons were also examined histologically. The behaviour of the relevant species was studied, with particular reference to the extent and frequency of forward-reaching and overhead activity of the forelimb. In quadrupedal species, the tendons of supraspinatus, infraspinatus and teres minor were seen to insert into the greater tuberosity of the humerus separately. They therefore did not form a true rotator cuff with blending of the tendons. This was only found in advanced primates and in one unusual species, the tree kangaroo. These findings support the suggestion that the appearance of the rotator cuff in the evolutionary process parallels anatomical adaptation to regular overhead activity and the increased use of the arm away from the sagittal plane

Aims. In patients with a rotator cuff tear, tear pattern and tendon involvement are known risk factors for the development of pseudoparalysis of the shoulder. It remains unclear, however, why similar tears often have very different functional consequences. The present study hypothesizes that individual shoulder anatomy, specifically the moment arms (MAs) of the rotator cuff (RC) and the deltoid muscle, as well as their relative recruitment during shoulder abduction, plays a central role in pseudoparalysis. Materials and Methods. Biomechanical and clinical analyses of the pseudoparalytic shoulder were conducted based on the ratio of the RC/deltoid MAs, which were used to define a novel anatomical descriptor called the Shoulder Abduction Moment (SAM) index. The SAM index is the ratio of the radii of two concentric spheres based on the centre of rotation of the joint. One sphere captures the humeral head (numerator) and the other the deltoid origin of the acromion (denominator). A computational rigid body simulation was used to establish the functional link between the SAM index and a potential predisposition for pseudoparalysis. A retrospective radiological validation study based on these measures was also undertaken using two cohorts with and without pseudoparalysis and massive RC tears. Results. Decreased RC activity and improved glenohumeral stability was predicted by simulations of SAM indices with larger diameters of the humeral head, being consequently beneficial for joint stability. Clinical investigation of the SAM index showed significant risk of pseudoparalysis in patients with massive tears and a SAM < 0.77 (odds ratio (OR) 11). Conclusion. The SAM index, which represents individual biomechanical characteristics of shoulder morphology, plays a determinant role in the presence or absence of pseudoparalysis in shoulders with massive RC tears

Recognized anatomic variations that lead to patella instability include patella alta and trochlea dysplasia. Lateralization of the extensor mechanism relative to the trochlea is often considered to be a contributing factor; however, controversy remains as to the degree this contributes to instability and how this should be measured. As the tibial tuberosity-trochlear groove (TT-TG) is one of most common imaging measurements to assess lateralization of the extensor mechanism, it is important to understand its strengths and weaknesses. Care needs to be taken while interpreting the TT-TG value as it is affected by many factors. Medializing tibial tubercle osteotomy is sometimes used to correct the TT-TG, but may not truly address the underlying anatomical problem. This review set out to determine whether the TT-TG distance sufficiently summarizes the pathoanatomy, and if this assists with planning of surgery in patellar instability.

Cite this article: Bone Jt Open 2022;3(3):268–274.

Aims

The aim of this study was to compare the characteristics and outcomes of L-shaped and reverse L-shaped rotator cuff tears.

Achilles tenotomy is a recognised step in the Ponseti technique for the correction of idiopathic congenital talipes equinovarus in most percutaneous cases. Its use has been limited in part by concern that the subsequent natural history of the tendon is unknown. In a study of 11 tendons in eight infants, eight tendons were shown to be clinically intact and ten had ultrasonographic evidence of continuity three weeks after tenotomy. At six weeks after tenotomy all tendons had both clinical and ultrasonographic evidence of continuity

Conventional non-steroidal anti-inflammatory drugs (NSAIDs) and newer specific cyclo-oxygenase-2 (cox-2) inhibitors are commonly used in musculoskeletal trauma and orthopaedic surgery to reduce the inflammatory response and pain. These drugs have been reported to impair bone metabolism. In reconstruction of the anterior cruciate ligament the hamstring tendons are mainly used as the graft of choice, and a prerequisite for good results is healing of the tendons in the bone tunnel. Many of these patients are routinely given NSAIDs or cox-2 inhibitors, although no studies have elucidated the effects of these drugs on tendon healing in the bone tunnel. In our study 60 female Wistar rats were randomly allocated into three groups of 20. One received parecoxib, one indometacin and one acted as a control. In all the rats the tendo-Achillis was released proximally from the calf muscles. It was then pulled through a drill hole in the distal tibia and sutured anteriorly. The rats were given parecoxib, indometacin or saline intraperitoneally twice daily for seven days. After 14 days the tendon/bone-tunnel interface was subjected to mechanical testing. Significantly lower maximum pull-out strength (p < 0.001), energy absorption (p < 0.001) and stiffness (p = 0.035) were found in rats given parecoxib and indometacin compared with the control group, most pronounced with parecoxib

Aims

This study aimed to investigate the relationship between changes in patellar height and clinical outcomes at a mean follow-up of 7.7 years (5 to 10) after fixed-bearing posterior-stabilized total knee arthroplasty (PS-TKA).

Aims. The aim of the study was to analyze the results of primary tendon reinsertion in acute and chronic distal triceps tendon ruptures (DTTRs) in the general population. Patients and Methods. A total of 28 patients were operated on for primary DTTR reinsertions, including 21 male patients and seven female patients with a mean age of 45 years (14 to 76). Of these patients, 23 sustained an acute DTTR and five had a chronic injury. One patient had a non-simultaneous bilateral DTTR. Seven patients had DTTR-associated ipsilateral fracture or dislocation. Comorbidities were present in four patients. Surgical treatment included transosseous and suture-anchors reinsertion in 22 and seven DTTRs, respectively. The clinical evaluation was performed using Mayo Elbow Performance Score (MEPS), the modified American Shoulder and Elbow Surgeons Score (m-ASES), the Quick Disabilities of the Arm, Shoulder and Hand score (QuickDASH), and the Medical Research Council (MRC) Scale. Results. A total of 27 patients (28 DTTRs) were available for review at a mean of 47.5 months (12 to 204). The mean MEPS, QuickDASH, and m-ASES scores were 94 (60 to 100), 10 (0 to 52), and 94 (58 to 100), respectively. Satisfactory results were observed in 26 cases (93%). Muscle strength was 5/5 and 4/5 in 18 and ten DTTRs, respectively. One patient with chronic renal failure experienced a traumatic rerupture of distal triceps. One patient (1 DTTR) experienced mild elbow stiffness. Conclusion. Primary repair of acute and chronic DTTRs in a general population yields satisfactory results in the majority of patients with a low rerupture rate. Cite this article: Bone Joint J 2018;100-B:610–16

Aims. Flexor hallucis longus (FHL) tendon transfer is a well-recognized technique in the treatment of the neglected tendo Achillis (TA) rupture. Patients and Methods. We report a retrospective review of 20/32 patients who had undergone transtendinous FHL transfer between 2003 and 2011 for chronic TA rupture. Their mean age at the time of surgery was 53 years (22 to 83). The mean time from rupture to surgery was seven months (1 to 36). The mean postoperative follow-up was 73 months (29 to 120). Six patients experienced postoperative wound complications. Results. The mean postoperative Achilles tendon Total Rupture Score (ATRS) was 83 (40 to 100) and the mean American Orthopaedic Foot & Ankle Society (AOFAS) score was 94.3 (82 to 100). Tegner scoring showed a mean reduction of one level from the pre-injury level of activity. There was a mean reduction of 24% (4 to 54) in dynamometer-measured strength of ankle plantarflexion, in comparison with the non-operated side. The hallux had a mean of only 40% (2 to 90) strength of plantarflexion in comparison with the contralateral side. Conclusion. We conclude that transtendinous FHL transfer for neglected TA ruptures, with a long harvest to allow reattachment of the triceps surae, provides reliable long-term function and good ankle plantarflexion strength. Despite the loss of strength in hallux plantar flexion, there is little comorbidity from the FHL harvest. Cite this article: Bone Joint J 2018;100-B:584–9

Aims

Long-term outcomes following the use of human dermal allografts in the treatment of symptomatic irreparable rotator cuff tears are not known. The aim of this study was to evaluate these outcomes, and to investigate whether this would be a good form of treatment in young patients in whom a reverse shoulder arthroplasty should ideally be avoided.